Chapter 3 What is Ecology? Prentice Hall P.60-85

Chapter 3 What is Ecology ? SOL 9 The branch of biology that developed from natural history is called ecology. Ecology is the study of interactions that take place between organisms and their environment. Section 2.1 Summary – pages 35 - 45

The Biosphere The biosphere is the portion of Earth that supports living things. It extends from high in the atmosphere to the bottom of the oceans.

The nonliving environment: Abiotic factors The nonliving parts of an organism’s environment are the abiotic factors. Examples: air currents, temperature, moisture, light, and soil. Prentice Hall introduces abiotic and biotic in Chapter 4 (4-2 p. 90)

The living environment: Biotic factors A key consideration of ecology is that living organisms affect other living organisms All the living organisms that inhabit an environment are called biotic factors. All organisms depend on others directly or indirectly for food, shelter, reproduction or protection.

Levels of Organization Ecologists study individual organisms, interactions among organisms of the same species, interactions among organisms of different species, as well as the effects of abiotic factors on interacting species. Ecologists have organized the living world into levels the Organism by itself (species), Population- all members of one species in an area Community- all populations in a given area Ecosystem- community + the nonliving factors (ABIOTIC) Biome –ecosystems with similar climate and similar dominant communities Biosphere – biotic + abiotic factors of the entire Earth

Levels of Organization

Observing – use of one or more of the senses to gather information Ecological Methods Observing – use of one or more of the senses to gather information Experimenting –testing hypotheses either in the lab or in the field Modeling – involves constructing a representation of an object, a system or a process that helps show relationships among data = an explanation supported by data Modeling often consists of mathematical formulas

Ecological Methods Observation Experiment Model Building Sites Field site Experimental plots, field sites, laboratory Many sites for data collecting Measuring Tools Tapes, compass, Global Positioning System, thermometer, sensors Aerial views, Global Positioning System, weather balloons Magnifying Tools Binoculars, microscope, telescope Satellite images Written Record Notes, automated data storage Automated data storage Chemical Testing Test kits Large database, multiple sensors Computer/ Calculators Mathematical analysis and graphics, statistics and graphics, statistics, simulations

Ecological research Ecologists obtain quantitative data by making measurements and carrying out controlled experiments in the field and in the laboratory.

Question 1 A. abiosis B. symbiosis C. ecology D. biology The study of interactions that take place between organisms and their environment is __________. A. abiosis B. symbiosis C. ecology D. biology Section 1 Check

The answer is C. Ecology is a branch of biology that developed from natural history. Section 1 Check

Question 2 A. moisture B. soil C. earthworm D. light Which of the following is a biotic factor? A. moisture B. soil C. earthworm D. light Section 1 Check

The answer is C. Biotic factors are all the living organisms that inhabit an environment. Section 1 Check

Question 3 A. biological community B. population C. ecosystem A(n) __________ is a group of organisms, all of the same species, which interbreed and live in the same place at the same time. A. biological community B. population C. ecosystem D. habitat Section 1 Check

The answer is B. Communities and ecosystems are comprised of more than one species. Habitat refers to the place an organism lives. Section 1 Check

Question 4 Which type of organism consumes both plant and animal products? A. herbivore B. carnivore C. predator D. omnivore Chapter Assessment

The answer is D. Humans are omnivores and eat a variety of foods that include both plant and animal materials. The figure shows recommended food servings for good health. Chapter Assessment

Energy Flow All organisms need energy for life activities This energy comes from their food. Consumption of food is an energy transfer Food Chains Food Webs

The producers: Autotrophs The ultimate source of the energy for life is the sun. Plants use the sun’s energy to manufacture food in a process called photosynthesis.

Good Time to review Chemical Equations ( Reactants and Products)

Chemosynthesis – use chemical energy to produce food instead of light Life Without Light

The producers: Autotrophs An organism that uses light energy or energy stored in chemical compounds to make energy-rich compounds is a producer, or autotroph Other organisms in the biosphere depend on autotrophs for nutrients and energy. These dependent organisms are called consumers or heterotrophs

The consumers: Heterotrophs An organism that cannot make its own food and feeds on other organisms is called a heterotroph A heterotroph that feeds only on plants is an herbivore. Some heterotrophs eat other heterotrophs. Animals such as lions that kill and eat only other animals are carnivores. Detritivores- eat dead plants and animals (detritus) Ex: mites, earthworms, snails, crabs Some organisms, such as bacteria and fungi, are decomposers. Decomposers break down the complex compounds of dead and decaying plants and animals into simpler molecules that can be more easily absorbed.

Producers: organisms that make their own food

Herbivore: animal that eats plants (Primary Consumer)

Carnivore: animal that eats other animals (Secondary consumer, Tertiary consumer, Quaternary consumer etc)

Decomposer: an organism that feeds on dead organic material

Detritivore (Scavenger): consumer that feeds on remains of dead organisms Detritivores – dee-TRYT-uh-vawrz

Flow of Matter and Energy in Ecosystems A food chain is a simple model that scientists use to show how matter and energy move through an ecosystem. In a food chain, nutrients and energy move from autotrophs to heterotrophs and, eventually, to decomposers. A food chain is drawn using arrows to indicate the direction in which energy is transferred from one organism to the next. Most food chains consist of two, three, or four transfers. The amount of energy remaining in the final transfer is only a portion of what was available at the first transfer. A portion of the energy is given off as heat at each transfer.

Simple Food Chain

Trophic levels represent links in the chain Each organism in a food chain represents a feeding step, or trophic level, in the passage of energy and materials Primary Consumer (Herbivore)(first order heterotroph) is an organism that feeds on plants, such as a grasshopper. Secondary Consumer (Carnivore) (A second order heterotroph) is an organism that feeds on a first order heterotroph. A food chain represents only one possible route for the transfer of matter and energy through an ecosystem.

Food web A food web, shows all the possible feeding relationships at each trophic level in a community.

Three different types of Ecological Pyramids: An ecological pyramid shows the amount of energy or matter in an ecosystem. Shows relative amounts of energy or matter contained in each trophic level The base of the ecological pyramid represents the autotrophs, or first trophic level. Higher trophic levels are layered on top of one another. Three different types of Ecological Pyramids: 1. Energy 2. Biomass 3. Pyramid of Numbers

Energy pyramids The pyramid of energy illustrates that the amount of available energy decreases at each succeeding trophic level. the total energy transfer from one trophic level to the next is only about ten percent because organisms fail to capture and eat all the food energy available at the trophic level below them. 2. They use much of the energy for life processes 3. Some of the energy is released as heat

Pyramid of Energy Section 2.2 Summary – pages 46 - 57

Pyramid of Biomass A Pyramid of Biomass is the total weight of living matter at each trophic level. 1 kilogram of human tissue 10 kilograms of beef 100 kilograms of grain Section 2.2 Summary – pages 46 - 57

Biomass Pyramid

Pyramids of Numbers A pyramid of numbers shows that population sizes decrease at each higher trophic level. Fox (1) Birds (25) Grasshoppers (250) Grasses (3000) Section 2.2 Summary – pages 46 - 57

Question 5 A. autotroph B. heterotroph C. decomposer D. herbivore Which of the following is a producer? Chloroplast A. autotroph Nucleus Mitochondrion B. heterotroph Eyespot C. decomposer D. herbivore Flagellum Pellicle Contractile vacuole Section 2 Check

The answer is A. Organisms that make energy-rich compounds are producers, or autotrophs. Chloroplast Nucleus Mitochondrion Eyespot Flagellum Pellicle Contractile vacuole Section 2 Check

Question 6 A. autotrophs, autotrophs B. autotrophs, heterotrophs In a food chain, nutrients and energy move from __________ to __________. A. autotrophs, autotrophs B. autotrophs, heterotrophs C. heterotrophs, autotrophs D. decomposers, autotrophs Section 2 Check

The answer is B. The first level in all food chains is made up of producers. berries → mice → black bear Section 2 Check

Question 7 A. food pathway B. food chain C. food matrix D. food web A model of all the possible feeding relationships at each trophic level in a community is a(n) __________. A. food pathway B. food chain C. food matrix D. food web Section 2 Check

The answer is D. A food web is a more realistic model than a food chain, because most organisms depend on more than one other species for food. Section 2 Check

Question 8 Which of the following models best illustrates heat released at each trophic level of an ecosystem? A. food chain B. food web C. pyramid of energy D. pyramid of biomass Chapter Assessment

The answer is C. The pyramid of energy shows energy available The answer is C. The pyramid of energy shows energy available. Organisms at each trophic level use some energy in food for metabolism and some is given off as heat. The total amount of energy remains the same in accordance with the law of conservation of energy. Pyramid of Energy Heat 0.1% Consumers Heat 1% Consumers 10% Consumers Heat 100% Producers Heat Parasites, scavengers, and decomposers feed at each level. Chapter Assessment

Question 9 Compare the amount of energy available in the biosphere to the amount of matter here. Chapter Assessment

ANSWER Both energy and matter are conserved: they may be transformed, but are not destroyed. However, sunlight is the primary source of all the energy utilized and transferred in the biosphere. It is always being replenished by the sun. In contrast, there is a finite amount of matter in the biosphere, which is cycled and not replenished. Chapter Assessment

Cycles in Nature Matter, in the form of nutrients, moves from one organism to another and from one part of the biosphere to another through biogeochemical cycles, Matter is cycled and is not replenished like the energy from sunlight. There is a finite amount of matter.

Major Processes in Water Cycle 1. Precipitation- water vapor condensing and falling from the atmosphere 2. Evaporation – liquid water changing to a gas 3. Transpiration- water evaporating from plants The cycling of water is driven by heat from the sun

The Water Cycle Condensation Precipitation Evaporation Transpiration Runoff Seepage Root Uptake

The Water Cycle In the water cycle, water is constantly moving between the atmosphere and Earth. Condensation Evaporation Precipitation Transpiration Runoff Evaporation Oceans Groundwater Section 2.2 Summary – pages 46 - 57

Water Cycle

Carbon Cycle Carbon and Oxygen combine to form Carbon Dioxide. Plants use Carbon Dioxide during photosynthesis to produce sugars. Plants use sugars for plant growth & respiration Herbivores eat plants, and incorporate molecules into their structures. Respiration breaks down sugars releasing CO2 and water back into the atmosphere.

Carbon Cycle Major Processes are: 1. Photosynthesis: 6 CO2 + 6 H2O  C6H12O6 + 6 O2. Carbon Dioxide Water Glucose Oxygen 2. Respiration: C6H12O6 + 6 O2  6 CO2 + 6 H2O Glucose Oxygen Carbon Dioxide Water

Carbon Cycle

Nitrogen Cycle Relies heavily on bacteria Atmosphere major reservoir-78% N2 Nitrogen found in proteins and DNA, RNA Plants need nitrogen in the form of nitrate ( NO3) Animals get nitrogen from proteins in their food

Bacteria of the Nitrogen Cycle 1. Nitrogen-fixing bacteria -convert N2 in air to nitrates that plants can absorb and use Symbiotic with legumes-found in nodules in roots of peas, beans, and clover 2. Bacteria of Decay - Decomposers- convert nitrogenous wastes into ammonia (NH3) 3. Nitrifying bacteria – convert ammonia to nitrates Denitrifying bacteria – break down nitrogen compounds into free nitrogen which returns to the atmosphere

The nitrogen cycle In the nitrogen cycle, nitrogen is converted from a gas to compounds important for life and back to a gas. N2 in Atmosphere NO3 & NO2 NH3

Nitrogen Cycle

Phosphorus Cycle Main abiotic reservoir for phosphorus is rock Weathering of rock adds phosphorus to soil Plants absorb phosphates from soil and build organic compounds (ATP, DNA, bones) Animals eat plants –incorporate phosphates in to animal compounds Is not cycled in the atmosphere!

Phosphorus Cycle

Nutrient Limitation Primary productivity = rate at which organic matter is created by producers Limiting nutrient – a needed nutrient is in short supply- will affect growth and reproduction of organisms Open Oceans – nutrient poor Sea Water contains 0.00005% Nitrogen (1/10,000 of amount usually found in soil) Algal bloom – sudden increase in limiting factor causes sudden large increase in population of algae

Chlorella Algae

Question 10 Which of the following does not cycle into the atmosphere? A. phosphorus B. nitrogen C. carbon D. water Chapter Assessment

The answer is A. Phosphorus moves between the living and nonliving parts of the environment, but does not enter the atmosphere as a gas. Chapter Assessment

Question 11 How does water on Earth's surface get back into the atmosphere? Condensation Evaporation Precipitation Transpiration Runoff Evaporation Oceans Groundwater Chapter Assessment

ANSWER The processes of evaporation of water in lakes and oceans and transpiration by plants both put water vapor into the air. Condensation Evaporation Precipitation Transpiration Runoff Evaporation Oceans Groundwater Chapter Assessment